Wireless Channel Direction Quantization With Scalable Vector Refinement

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Solution Overview

Problem

Existing directional vector quantization techniques perform single-stage quantization with fixed resolution, failing to adaptively refine vector representation during encoding, especially in applications requiring dynamic accuracy and efficient resource utilization, such as mobile stations reporting channel directions to base stations.

Innovation Solution

A scalable spherical vector quantization scheme using off-the-shelf codebooks of decreasing dimensions, allowing incremental refinement of vector direction representation with the same set of quantization codebooks, reducing encoding complexity and enabling efficient resource use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If single-stage quantization with fixed resolution is used, then device complexity is reduced, but adaptability and measurement precision deteriorate

Engineering Contradiction:
Improvequantization scheme complexityVSAvoiddynamic accuracy adjustment
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by dividing the single-stage quantization process into multiple refinement stages. Each stage processes a portion of the vector components sequentially, allowing the system to achieve adaptive resolution without requiring a completely different quantization scheme for each accuracy level. The first stage quantizes initial components, and subsequent stages refine by quantizing additional components, enabling dynamic accuracy adjustment while maintaining manageable device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamics by making the quantization resolution adjustable through selective application of refinement stages. The system can dynamically adapt the number of refinement stages based on channel conditions, feedback requirements, and resource availability. This allows the quantization scheme to transition from coarse to fine resolution on demand, providing versatility without requiring multiple fixed-resolution systems.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If multiple codebooks of different dimensions are used for refinement stages, then measurement precision improves, but device complexity and loss of information increase

Engineering Contradiction:
Improvevector direction quantization accuracyVSAvoidcodebook management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by using a single codebook for all refinement stages instead of maintaining multiple codebooks of different dimensions. The same codebook is applied iteratively to quantize components at each refinement stage, eliminating the need for separate codebook management. This universal approach maintains measurement precision through multiple refinement passes while significantly reducing device complexity associated with storing and managing multiple codebooks.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functionality of multiple dimension-specific codebooks into a single unified codebook that serves all refinement stages. Instead of having separate codebooks for different vector dimensions, the system combines their functionality by applying the same codebook repeatedly with different input components. This consolidation reduces memory requirements and simplifies codebook management while maintaining the precision benefits of multi-stage refinement.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If hierarchical codebook construction with nested structure is used, then measurement precision improves, but device complexity and manufacturing precision requirements increase

Engineering Contradiction:
Improveincremental refinement accuracyVSAvoidcodebook design and implementation
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent inverts the traditional hierarchical codebook approach by using a single codebook iteratively rather than constructing nested hierarchical structures. Instead of building codebooks with nested relationships where finer codebooks are embedded within coarser ones, the system applies the same codebook in sequence across refinement stages. This inversion simplifies codebook design and implementation while maintaining incremental refinement accuracy, making the system easier to manufacture and deploy.

Inventive Principle:
Principle #13The other way round (Inversion)

4Loss of information

If differential encoding is applied to correlated vectors, then loss of information is reduced, but device complexity and ease of operation worsen

Engineering Contradiction:
Improveredundant information in correlated vectorsVSAvoidencoding operation complexity
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The patent applies the extraction principle by removing redundant information from correlated vectors through iterative quantization of individual components. Instead of implementing complex differential encoding algorithms that explicitly model correlations, the system extracts essential information by sequentially quantizing components and using refinement stages to capture incremental improvements. This approach reduces information loss while keeping encoding operations simpler than traditional differential encoding methods.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS9184950B2Wireless communication apparatus
Publication Date: 2015.11.10 KK TOSHIBA
  • US9184950B2 patent drawing
  • US9184950B2 patent drawing
  • US9184950B2 patent drawing

AI summary

Processing data presented in the form of a vector representation involves representing direction of the vector with incremental accuracy by using a set of vector codebooks of decreasing dimensions per accuracy increment.